Sprockets is a Rack-based asset packaging system that concatenates and serves JavaScript, CoffeeScript, CSS, Sass, and SCSS.

Ruby CoffeeScript is a bridge to the JS CoffeeScript compiler.

Uglifier minifies JavaScript files by wrapping UglifyJS to be accessible in Ruby

Use webpack to manage app-like JavaScript modules in Rails

If you need to send some data to your js files and you don't want to do this with long way trough views and parsing - use this force!

Opal is a Ruby to JavaScript compiler. It is source-to-source, making it fast as a runtime. Opal includes a compiler (which can be run in any browser), a corelib and runtime implementation. The corelib/runtime is also very small.

Wiselinks makes following links and submitting some forms in your web application smarter and faster

Rails bindings for opal JS engine

Resolve dependencies, merge and minify CSS and JavaScript files with Juicer - the command line tool for frontend engineers

Barista provides simple, integrated support for CoffeeScript in Rack and Rails applications. Much like Compass does for Sass, It also provides Frameworks (bundleable code which can be shared via Gems). Lastly, it also provides a Rack Application (which can be used to server compiled code), a around_filter-style precompiler (as Rack middleware) and simple helpers for rails and Haml. For more details, please see the the README file bundled with it.

Mousetrap is a javascript library for handling keyboard shortcuts in your web applications. This gem integrates Mousetrap with Rails asset pipeline for easy of use.

Keep your vendor files up to date

Page-specific javascript for Rails done right

Build tools for JavaScript projects

JavaScript/CSS/HTML sources compiler

Inspiredby HAML, SASS and JABL by mr Hampton Catlin

Ruby version of Dean Edwards' JavaScript compressor

A rake task to minify javascripts and coffeescripts

Stupidly simple command line tool for squashing JS and CSS files. Used mostly for building UserJS

Better Unobtrusive JavaScript Respond

jQuery CDN script tags and fallback in one neat package. Current version is for jQuery v2.1.0

Auto-magical scaffolding for the Garber-Irish Implementation way of organizing your javascript.

Auto-magical scaffolding for Paul Irish's DOM-based Routing way of organizing your javascript.

A light wrapper for using dynamo.js with Ruby on Rails

Rack middleware that executes javascript before serving pages to crawlers.